Valve.



No. 663,275. Patented Dec. 4, I900. J. HOPKINSUN & J. LOWIS.

VALVE.

(Application filed Aug. 21', 1900.)

(No Model.) 2 Sheets-Sheet 2.

Urvritnn STATES Erica.

ATENT JOSEPH HOPKINSON AND JOHN LOWIS, OF HUDDERSFIELD, ENGLAND,ASSIGNORS TO THE J. I-IOPKINSON dz COMPANY, LIMITED, QF SAME PLACE.

VALVE.

SPECIFICATION forming part of Letters Patent No. 663,275, dated December4:, 1900.

Application filed August 21, 1900. Serial No. 27,571. (No model.)

To all whom, it ntcty concern:

Be it known that we, JOSEPH HOPKINSON, engineer, and JOHN LOWIs, worksmanager, subjects of the Queen of Great Britain, residing atHuddersfield, in the county of York, England, have invented certain newand usefullmprovements RelatingtoValves,ofwhich the following is aspecification.

In the construction of screw-down valves of the mushroom type, parallelslide and other stop-valves, safetywalves, and the like with seat-ringsmade of a metal which is different from and has a greater coefficient ofexpansion than that of which the valve casing or body is madedifficulties arise owing to the differences of expansion and contractionbetween the valve-body and the seatring when they are subjected to greatvariations of temperature, as is the case when the same are used inconnection with high-pressure steam plants. A common method ofconstructing such valves is to force the seat-ring into a recessprovided for it in the valve body or casing; but it is obvious that suchmethod does not provide for allowing the ring to expand when subjectedto high temperature, and therefore many difficulties and troubles wellknown to engineers arise. We have heretofore employed a method ofconstructing compound valve-seats having for its object the avoidance ofthe difficulties and troubles above referred to, the seat-ring beingfree to expand and contract in accordance with the variations oftemperature to which the valve is subjected when at work. The preferredmode of constructing the seats according to this method is asfollowsthat is to say, a projection is formed around the orifice orpassage through the casing or valvebody, such projection being either anintegral part of the casing itself or formed on a separate ring driveninto a recess provided for it in the casing, such ring being intended toremain permanently in the said recess and being formed of a metal thesame as that of the valve body or casing, or of a metal havingsubstantially the same coefficient of expansion as the metal of thecasing. The top or face of this projection is suitably faced and groundafter the ring is fixed in the valvebody, and the outer circumference ofthe projection is screw-threaded or otherwise so constructed that aseat-ri ng proper can be screwed or attached thereto, the said seat-ringhaving an internal flange which is faced on its lower side to fitclosely upon the aforesaid faced surface of the fixed ring orprojection, so that when the seat-ring is screwed home upon the fixedring the two faces thereof come together and form a fluid-tightmetal-to-metal joint. The upper face of the seat-ring is prepared in asuitable manner to form the valve-seat proper. In this method ofconstruction the fixed ring and the seat-ring are liable to be distortedin the process of manufacture and in the operation of fitting them inthe valvebody, so that when the seat-ring is screwed down a perfectmetal-tometal fluid-tight joint between the two planes of the seat-ringand fixed ring is not insured. Our present invention, while obviatingthe defects above referred to, accomplishes all the objects of saidmethod and also embodies other advantageous features whereby compoundvalveseats are made more efficient, less liable to strains and stresses,easier and more certain of manufacture, and at the same time the seatsare easier to remove, renew, and replace without requiring thevalve-body to be dismounted.

In the accompanying drawings,which illustrate our present invention,Figure l is a central section of a portion of a mushroom type screw-downstop-valve fitted with our improved valve-seat. Fig. 2 is a similar Viewof a dead-weight safety-valve, and Fig.

3 is a central section of a parallel-slide stopvalve.

Like letters of reference denote corresponding parts in the severalfigures.

A is the valve body or casing. valve proper.

For the purposes of our invention we provide around the orifice orpassage 0 of the valve-casing which is to receive the seat, as in themethod above referred to, an annular projection D, formed integrallywith the casing A, as shown in Fig. 2, or formed by a ring which isforced into a recess provided to receive it in the said casing, as shownin Figs.

B is the 1 and 3, said ring being made of the same metalas the casing orof a metal having substantially the same coeflicient of expansion as themetal of the casing. The outer ciroumference of the projection D isscrewthreaded, as shown, or it may be provided with interruptedscrew-threads or with ears or projections equivalent to screw-threads,and the upper face or end (I of the ring or projection is suitablyground and faced, so as to be capable of making a fluid-tight joint.Upon the end of the said projection We apply the seat-ring proper, E,which may be of brass, for example, having a substantially uniformsection and the lower face 6 of which is ground and faced to make afluidtight joint with the face 61 of the aforesaid projection D. Thesaid ring E has formed on it an external flange e, and the same issecured upon the projection D by means of an external ring F, whichpasses over the seat-ring E and screws upon the outer circumference ofthe said projection D. The retaining-ring F has formed on it an internalflange f, which when the said ringis screwed upon the projection D bearsupon the external flange e of the seat-ring, thereby holding theseat-ring in place. By this method of construction the seat-ring Ecannot be distorted, and therefore the upper face of said ring, which issuitably ground and faced to form the valve-seat proper, remainsperfectly true when fixed in position,while at the same time theseat-ring, as well as the retaining-ring F, is free to expand andcontract as may be required by the variations of temperature to whichthe valve is subjected. The retaining-ring is entirely external to the'seata-iug and is not in any way restrained circumferentially. When thevalve-body and the projection D are constructed of iron or steel, forexample, and the seat-ring E is made of gun-metal or the like having agreater coeflicient of expansion than the projection D, we make theretaining-ring of a metal also having a greater coefficient of expansionthan the projection D and preferably the same as the ring E.

Our invention is specially intended for valves in which the seat-ring ismade of metal diiferen t from that of the valve body or casin g.

\Vhere necessary or desirable, the retainin g-ring is furnished withguide-bars for guiding the valve.

In Fig. 3 we have shown the slide-valve B furnished with detachablerings 5 on its faces, similar to the seat-rings E and secured to thevalve by retaining-rings 1), similar to the retaining-rings F. Thisconstruction is specially applicable to large valves when it is notdesired to make the whole of the valve of gun-metal.

What we claim is 1. In'a valve, the combination, with the valve-body, ofan annular projection formed around the orifice or passage through thebody, a seat-ring resting on the outer face of said projection, and aretaining-ring surroundingsaid seat-ring and having a connection withsaid projection, substantially as described. V

2. In a valve, the combination, with the valve-body,of a ring secured ina recess aroun (l the orifice or passage through the body, an annularprojection on said ring, a seat-ring resting on said projection, and aretainingring surrounding and partially overhanging said seat-ring andsecured on the outside of the said projection ,su bstantially asdescribed.

3. In a valve, the combination, with the valve body or casing, of anannular projection formed around the orifice or passage through thebody, a seat-ring resting on said projection, an external flange on saidseatring, a retaining-ring surrounding said seatring and having aninternal flange resting on the external flange of the seat-ring, andscrewthreads on the outside of the annular projection engaging internalscrew-threads in the retaining-ring, substantially as-,described.

4. In a valve, the combination, with the valve proper, of a detachableface having an external flange, a retaining-ring surrounding thedetachable face and having an internal flange resting on the externalflange of the detachable face, said retaining-ring being secured to thevalve by screwing, substantially as described.

5. In a valve, the combination with the valve-casing having an annularprojection formed around the passage through said casing, of adetachable seat ring resting on said projection, an annular flange onsaid seatring, and a flanged retaining-ring having a connection with theflange on the seat-ring and with the said annular projection,substantially as described.

In testimony whereof we have hereunto set our hands in presence of twosubscribing witnesses.

JOSEPH HOPKINSON. JOHN LOlVIS. I

Witnesses:

GEORGE HELM, O. E. HOBSON.

